When I wanted to learn something new, I used to go and buy 10 books on the subject. I would find something useful in all of them, but rarely, in fact never, did

When I wanted to learn something new, I used to go and buy 10 books on the subject. I would find something useful in all of them, but rarely, in fact never, did a single book have everything I needed. And half the books would rubbish. But $500 got me the information I needed. Now I go out and buy 10 Udemy courses and have the same experience: 5 are rubbish and maybe two cover everything I need.